VERA GROUP
Non-contact coating thickness measurement and booth integration
Surveys show that even today , less than 1 % of all powder coaters determine the layer thickness before baking or curing . The applied layer thickness is related to many external influencing parameters that cannot be completely controlled . These include , among other factors , the composition of the powder coating material , aging of wear parts , air pressure and the humidity . With otherwise fixed coating parameters , the layer thickness can fluctuate by more than 50 %. By classical means , an undercoating can only be prevented if more coating material is applied than necessary . This means more energy consumption , more CO2 emission and more cost .
If the layer thickness is measured immediately after the coating has been applied , the target layer thickness can be precisely matched . In practice , powder coating material of up to 30 % can be saved in this way . So far , many suppliers of non-contact coating thickness gauges have failed due to the high industrial requirements . The requirements include a high tolerance in handling , fast measuring process , so that measurements can also be taken on moving parts as well as a good agreement with comparative measurements in the burned-in state .
In September 2021 , a new edition of the Coatmaster Flex noncontact coating thickness gauge was introduced to the market . The measuring principle is based on Advanced Thermal Optics ( ATO ) where heat is applied to the surface over a large area by a barely visible light pulse . The heat transport through the coating is analyzed using high-speed infrared detectors and innovative algorithms . The coating thickness is determined from the propagation time of the thermal wave and the thermal properties of the coating material . were powder-coated in different RAL colors . After powder coating , the coating thickness was measured without contact using the set of preinstalled factory calibrations of the measurement system . The coatings were then cured and measured with a calibrated contact coating thickness gauge . A total of 10 measurement repetitions were carried out at each measuring position in order to determine the statistical measurement error of the two measurement methods . Figure 2 summarizes the results of the field trial .
Figure 2 : Comparison of the coating thickness measurement before ( Coatmaster- Flex ) and after curing ( contacting measuring method ) for different RAL colors , determined by the companies ( a-e ) participating in the field test .
The repeatability of the Coatmaster-Flex is on average 2.1 % of the displayed measured value across all measuring positions and 3.5 % of the contacting method . The layer thicknesses before baking show a high correspondence with the layer thicknesses after baking , regardless of the RAL color . In most cases , the deviation is only a few μm . Within the scope of repeatability , the measurement before curing is consistent with the measurement after curing . Particularly positive was the SpectralBlue ® technology , with which a completely glare-free work is possible .
Figure 1 : The coatmaster Flex in a field trial
58 FEBRUARY 2022
In Vera Makina , one of the leading Turkish system house paint line manufacturer , the field tests were performed , first we examined the measurement accuracy of the new Coatmaster Flex . For this purpose , test substrates made of 0.5mm aluminum sheet
An interesting feature of the coatmaster Flex is the possibility to process data directly in the cloud . In addition to the process documentation and the possibility to create reports , production orders can now be created directly in the cloud , so that the coater can focus on taking the measurement . After the measurement process , measurement reports can be automatically generated for
CONTINUED ON PAGE 60
twitter : @ surfaceworldmag